Directory assistance (DA) services, sometimes referred to as 411 services, enable users to find out the phone number associated with a business or residential listing. Currently, automatic DA services are becoming increasingly popular. A typical automatic DA system includes a recognition component configured to determine a query based on input from a user. The system then produces a ranked set of listings that correspond to the query.
Automatic DA services can run into problems related to listings that include compound words, for example a business listing containing a single word with multiple word components (e.g., outback or payless). In simple context free grammar (CFG) based approaches (i.e., where each listing corresponds to several rules in the CFG), compound words generally won't introduce big problems into the process of identifying matching listings. However, CFG based approaches can not be scaled well to large sets of listings, such as a set of listings associated with a large city.
For large sets of listings, an approach other than a CFG approach, such as an N-gram based approach, is commonly employed. Compound words can become a problem for many of these alternative approaches, including the N-gram based approach. For example, if a user inputs “outback” but it is recognized as “out back” or “out buck,” the DA system may have little or no chance of finding the desired listing, especially if the ranking index contains only “outback” for that listing.
The discussion above is merely provided for general background information and is not intended for use as an aid in determining the scope of the claimed subject matter.